CVE-2021-27256
NETGEAR R7800 Remote Code Execution Vulnerability
Description
This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R7800 firmware version 1.0.2.76. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the handling of the rc_service parameter provided to apply_save.cgi. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-12355.
INFO
Published Date :
March 5, 2021, 8:15 p.m.
Last Modified :
Nov. 21, 2024, 5:57 a.m.
Source :
[email protected]
Remotely Exploitable :
No
Impact Score :
5.9
Exploitability Score :
2.8
Affected Products
The following products are affected by CVE-2021-27256
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-27256.
| URL | Resource |
|---|---|
| https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders | Patch Vendor Advisory |
| https://www.zerodayinitiative.com/advisories/ZDI-21-262/ | Third Party Advisory VDB Entry |
| https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders | Patch Vendor Advisory |
| https://www.zerodayinitiative.com/advisories/ZDI-21-262/ | Third Party Advisory VDB Entry |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-27256 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-27256 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders Added Reference https://www.zerodayinitiative.com/advisories/ZDI-21-262/ -
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Initial Analysis by [email protected]
Mar. 16, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:A/AC:L/Au:N/C:C/I:C/A:C) Added CVSS V3.1 NIST AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Changed Reference Type https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders No Types Assigned https://kb.netgear.com/000062883/Security-Advisory-for-Multiple-Vulnerabilities-on-Some-Routers-Satellites-and-Extenders Patch, Vendor Advisory Changed Reference Type https://www.zerodayinitiative.com/advisories/ZDI-21-262/ No Types Assigned https://www.zerodayinitiative.com/advisories/ZDI-21-262/ Third Party Advisory, VDB Entry Added CPE Configuration AND OR *cpe:2.3:o:netgear:br200_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.10.0.5 OR cpe:2.3:h:netgear:br200:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:br500_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 5.10.0.5 OR cpe:2.3:h:netgear:br500:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:d7800_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.1.60 OR cpe:2.3:h:netgear:d7800:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex6100v2_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.1.98 OR cpe:2.3:h:netgear:ex6100v2:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex6150v2_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.1.98 OR cpe:2.3:h:netgear:ex6150v2:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex6250_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.0.134 OR cpe:2.3:h:netgear:ex6250:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex6400_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.2.158 OR cpe:2.3:h:netgear:ex6400:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex6400v2_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.0.134 OR cpe:2.3:h:netgear:ex6400v2:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex6410_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.0.134 OR cpe:2.3:h:netgear:ex6410:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex6420_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.0.134 OR cpe:2.3:h:netgear:ex6420:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex7300_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.2.158 OR cpe:2.3:h:netgear:ex7300:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex7300v2_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.0.134 OR cpe:2.3:h:netgear:ex7300v2:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex7320_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.0.134 OR cpe:2.3:h:netgear:ex7320:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex7700_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.0.216 OR cpe:2.3:h:netgear:ex7700:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:ex8000_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.1.232 OR cpe:2.3:h:netgear:ex8000:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:lbr20_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.3.50 OR cpe:2.3:h:netgear:lbr20:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:r7800_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.2.80 OR cpe:2.3:h:netgear:r7800:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:r8900_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.5.28 OR cpe:2.3:h:netgear:r8900:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:r9000_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.5.28 OR cpe:2.3:h:netgear:r9000:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk12_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.7.2.104 OR cpe:2.3:h:netgear:rbk12:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk13_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.7.2.104 OR cpe:2.3:h:netgear:rbk13:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk14_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.7.2.104 OR cpe:2.3:h:netgear:rbk14:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk15_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.7.2.104 OR cpe:2.3:h:netgear:rbk15:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk20_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbk20:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk23_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.7.2.104 OR cpe:2.3:h:netgear:rbk23:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk40_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbk40:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk43_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbk43:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk43s_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbk43s:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk44_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbk44:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk50_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.7.2.104 OR cpe:2.3:h:netgear:rbk50:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbk53_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.7.2.104 OR cpe:2.3:h:netgear:rbk53:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbr10_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbr10:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbr20_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbr20:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbr40_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbr40:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbr50_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.7.2.104 OR cpe:2.3:h:netgear:rbr50:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbs10_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbs10:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbs20_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbs20:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbs40_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbs40:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbs50_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.7.2.104 OR cpe:2.3:h:netgear:rbs50:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:rbs50y_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.6.2.104 OR cpe:2.3:h:netgear:rbs50y:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:xr450_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.3.2.114 OR cpe:2.3:h:netgear:xr450:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:xr500_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 2.3.2.114 OR cpe:2.3:h:netgear:xr500:-:*:*:*:*:*:*:* Added CPE Configuration AND OR *cpe:2.3:o:netgear:xr700_firmware:*:*:*:*:*:*:*:* versions up to (excluding) 1.0.1.38 OR cpe:2.3:h:netgear:xr700:-:*:*:*:*:*:*:* -
CVE Modified by [email protected]
Mar. 05, 2021
Action Type Old Value New Value Changed Description This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R7800 firmware version 1.0.2.76. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the handling of the rc_service parameter provided to apply_save.cgi. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-12355. This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of NETGEAR R7800 firmware version 1.0.2.76. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed. The specific flaw exists within the handling of the rc_service parameter provided to apply_save.cgi. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of root. Was ZDI-CAN-12355.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-27256 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-27256
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.22 }} 0.06%
score
0.59578
percentile